Most common forms

The type of cancer more frequently found in the colon and rectum is the adenocarcinoma – it comprises about 95% of all diagnosed colorectal cancers.

Like the name indicates, they are a form of carcinoma, what means that they appear on the tissue that covers internally or externally the organs. 

In the intestine, adenocarcinomas develop from the mucosa –the tissue that covers the intestine internally. 

As a result, the tumor grows inside the colon and rectum, leading to obstructions or hemorrhages. 

As the tumor grows, it invades the walls of the colon and can spread to neighboring organs.

Adenocarcinomas, which are 95% of all colorectal cancers, can be detected by simple colonoscopy.

This type of tumor develops from the goblet cells in the mucosa, which produce the mucus that lubricates and protects the intestine.

The remaining 5% colorectal cancers appear from other cells, and might not be unique to the intestine.